DESC: Simply add a subwoofer to complete your Blackstone TL150 system for the explosive low-frequency bass you need to get the most from today s digital media. Our PSW111 or PSWi225 make excellent choices. By the way, subwoofers can be hidden away in media furniture or behind your couch, so your compact sound system will never get in your way. You can also add individually available, perfectly timbre-matched Blackstone TL speakers to expand your system into the realms of 6.1, 7.1 and beyond!Time Lens technology-The acoustic centers of the tweeter and mid-bass driver are located in the same plane for superior imaging, while the acoustic lens incorporated in the grille smoothes the tweeter s frequency response. The TL Series creates imaging and frequency balance previously impossible in small, high performance satellite speakers.TL1 satellite aperiodic-tuned rear port enables better blending with a subwoofer.